Method of incorporating elastic thread in knitted fabrics



' June 5, 1945. J. GETAZ METHOD OF INCORPORATING ELASTIC THREAD 1N KNITTED FABRICS Filed Feb. 26, 1944 5 Sheets-Sheet 1 ATTORN EY J. L. GETAZ June 5, 1945.

METHOD OF INCORPORATING ELASTIC THREAD IN KNITTED FABRICS Filed Feb. 26, 1944 3 Sheets-Sheet 2 INVENTOR ATTORN EY Patented June 5, 1945 METHOD F INCORPORATING ELASTIC THREAD IN KNITTED FABRICS James L. Getaz, New York, N. Y. Application February 26,1944, Serial No. 524,018

Claims.

This invention is related to elastic knitted fabrics, particularly to elastic plain knit tops for hosiery.

This invention is an improvement on the method of incorporating elastic thread in the plain knit tops of hosiery as shown in my U. S. Patents 2,230,402, 2,230,403, 2,168,869 and 2,161,- 250. In using elastic thread in these knitted tops, it is desirable, in order to save the cost of elastic thread, to not use the elastic thread throughout each course of the knitted fabric, but to use the elastic thread in certain courses and omit this elastic thread from intervening courses, and by constructing the tops in this way important economy is obtained in the construction of these knitted fabrics.

In incorporating this elastic thread in sp courses, it has been customary to extend the elastic thread longitudinally from one spaced course to another, across the intervening courses, as shown in Figure No. 10 of my Patent No. 2,230,- 402. When the fabric is knitted, it is as shown in this Figure No. 10, but when the elastic th'read is allowed to assume its normal position in the fabric, it forms a straight line and distorts the shape and relative positions of the courses and wales of the knitted fabric at those points at which the elastic thread passes from one spaced course to another. In order to make these distorted portions of the fabric less conspicuous, it is customary to so time the movement of the parts of the knitting machines which control the placing of the elastic thread, that these distorted portions of the fabric are placed in the center of the back of the hose.

It is the purpose of this invention to provide a method of incorporating the elastic thread in plain knit tops, so as to obtain the same economy which is now obtained by putting the elastic thread only in spaced courses and to avoid the distortion of the knitted fabric, which is caused by extending the elastic thread across intervening courses. This is accomplished by incorporating the elastic thread in only a portion of each successive course of the knitted fabric, and extending the elastic thread from one course to the next, without any courses intervening. This method of incorporating the elastic thread in plain fabric produces a placing of the elastic thread in plain fabric, which is similar to that shown for ribbed fabric in my Patent No. 2,228,- 208.

In the accompanying drawings:

Figurel is a diagrammatic development of the knitting wave and knitting cams of a circular knitting machine embodying my invention, showing how the two yarns, the elastic yarn and the body thread, are fed to the needles.

Figure 2 is a plan view corresponding to Figure 1 showing the needle circle, and illustrating the manner in which the body thread and the elastic thread are fed to the needles, the small arrow indicating the knocking-over point.

Figure 3 is a side elevation of the parts indicated in Figure 2, showing the auxiliary thread feeding-finger for the elastic thread in operative and inoperative positions, and showing a side elevation of the knitting machine.

Figure 4 is a vertical section on the line 4-4 of Figure 3.

Figure 5 is a detail view of portions of the latch ring and auxiliary thread feeding finger, the latter being shown in operative position.

Figure 6 is a similar view to Figure 5 showing the inoperative position of the auxiliary feedingfinger.

Figure '7 is a section on line 1-1 of Figure No. 1 showing the elevation of the needles with reference to the elastic thread.

Figure 8 is a view of the top of a stocking made according to this invention, andwith an elastic selvage, as shown in my Patent 2,054,217, and co-pending application 201,861, filed April 14, 1938.

Figure 9 is an enlarged view of the fabric shown in Figure No. 8, in reversed position, the stitches in the bottom of this figure being knitted first.

My invention finds its greatest use in carrying out the invention disclosed in my Patent 2,230,- 402, above referred to, wherein the top portion of a stocking is knit by plain knitting and an elastic thread of rubber, or the well known Lastex, is interlaced with the needles and incorporated in the fabric in the first course to form an elastic selvage, and thereafter in spaced courses throughout a portion of a sock or stocking, to produce a formfitting and self-supporting tubular portion, usually the top of a sock or hose, which has for many years been formed of rib knitting, although it is to be understood that my invention is equally applicable to any other kind of hosiery and may be employed also for the purpose of introducing an inelastic thread, if that should be desirable. I, therefore, make no claim herein for the product disclosed in my said Patent 2,230,402.

Any circular knitting machine having cylinder needles with selectivity as between successive needles can be adapted to make this sock or stocking. Thus, the well known Scott 8; Williams type of revolving needle cylinder machine, such as shown for example in the United States Letters Patent to Robert W. Scott, No. 1,152,850, dated September '7, 1915, can be adapted to carry my present invention into effect, by the addition of the mechanism hereinafter described, for feeding the elastic thread and by properly adjusting the various cams.

In the drawings, the needle cylinder is indicated at C, and is provided with a circular series of needles, N, the upper ends of which, extending from the point of pivoting of the latch to the hook portion, are inclined forwardly with respect to the shank of the needles. Such needles can be obtained, and any of the so-called forward hook needles can be advantageously employed for this purpose. Each needle is provided with a butt 11, adapted to engage the knitting cams, indicated at 360, 351 and 36| respectively in the usual manner to effect the drawing of stitches by the hooks of the needles. Selected needles, in this case every alternate needle, are provided with a vertically disposed needle jack, indicated at 38l, and these jacks are provided with butts 11., adapted to engage a selecting cam, 368, located in advance of the throat, for the purpose of raising the alternate needles, which are designated by the number 2|, above the intervening needles, indicated by the numeral 22, at a point before the needles reach the throat. The throat is indicated at 560 in Fig. 2, and is provided with one or more thread feeding-fingers f, in the usual manner. L represents a latch ring, shown in section in Fig. 4, which is provided with a delivery eye Z, located in advance of the throat, through which the thread to be interlaced with the needles, and which in this instance is the elastic thread of rubber or Lastex, indicated at 20, may be delivered through the delivery eye of an auxiliary feeding-finger, hereinafter described, so as to pass in a line, approximately tangential to the circle of needles, and without sharp turns, to avoid placing any unnecessary friction on the thread. As shown herein the delivery eye I in the latch ring L extends through the latch ring angularly to a radius of the ring, and substantially tangential to the circle of the needle series. 30 represents the auxiliary thread feeding-finger, which is preferably pivotally mounted on some stationary part of the machine. It is here shown secured by a horizontal pivot 29 to one side of the throat 560, but it may be secured at any desired part. The thread feeding-finger 3|! is provided at its outer end with a downwardly extending plate portion 3|, which in its operative position lies against the inner face of the latch ring L, as shown in Fig. 4, and is provided with a delivery eye 32 at its lower end, adapted to register with the delivery eye I in the latch ring, and form a continuation thereof, so that the auxiliary thread 20 can pass freely through the registering delivery eyes I and 32, with an avoidance of sharp turns, as clearly shown in Fig. 2. The auxiliary thread, in this case the elastic thread 20, will be delivered from the supply spool in such a manner as to pass into the delivery eye of the latch ring in as nearly a straight line longitudinally thereof as practicable, and if found necessary or desirable, the latch ring, or some adjacent portion of the machine, may be provided with a grooved roller, indicated at 33, for this purpose, the thread 2|) passing to the roller as shown in full lines in Fig. 2, or otherwise, as indicated in one or other of the dotted lines 20a and 20b, according to the direction in which it comes from the spool. It will be understood that before passing through the resistering eyes I and 32, the elastic thread passes through a suitable tensioning device, indicated diagrammatically at T in Fig. 2, of any desired character. The auxiliary thread feeding-finger 30 will be provided with suitable means for automatically throwing it into and out of operation. In this instance it is shown provided with an arm 34, extending rearwardly of its point of pivoting and connected with a rod or link 35, operated by suitable cam (described below) for moving it from the operative position, shown in full lines in Figs. 3 and 5, to the inoperative position, shown in dotted lines in Fig. 3, and in full lines in Fig. 6. As indicated in the latter figure, when the feedflnger is moved to its inoperative position, it will lift the thread 20 out of a position in which it can be interlaced with the needles, in the manner previously described, and hold it until the auxiliary thread guide 30 is restored to its operative position, The knitting machine will also pref.- erably be provided with a clam and cutter of any desired form and operating in any suitable manner for holding the elastic thread when the auxiliary thread guide 30 is moved to inoperative position, and for severing it after the elastic thread has been fed to all of the courses desired in the stocking which is being knit. These parts are well known and are not herein shown. The body thread, which is fed to the hooks of all the needles, is indicated at 40 in Figs. 1 and 2, and is fed to the needles by one of the ordinary feedingfingers, I, located at the throat.

Assuming that the auxiliary thread guide 30 is in its operative position, and the elastic thread is supplied under desired tension to the registering delivery eyes I and 32, and that the machine is in operation, the butts n of the needle jacks 38| will engage the cam 366 and elevate alternate needles, as indicated at 2|, in Fig. l for example, sufficiently high to receive the elastic thread 20 below the latches thereof. The intervening needles 22 will not be elevated and will pass below the registering delivery eyes I and 32, and will not receive the elastic thread. As soon as the elastic thread 20 has been fed on the forward side of the needles 2|, below their latches, the butts of the intervening needles will engage the cam mechanism of the machine and the intervening needles will be raised to substantially the level of the needles 2|. As the needles 22 rise with respect to the needles 2 ,the forwardly bent hook portions of the needles 22 will pass in front of the elastic thread 20, as clearly shown in Fig. 7. The latch ring L is of suflicient depth so that it extends below the latches of the needles 2|, and any frictional engagement between the rising needles 22 and the elastic thread 20 will not have the effect of closing the latches of the adjacent needles 2|, which will be held from upward movement by engagement with the inner face of the latch ring. As the needles pass the throat, the thread guide, 1, thereof will feed the main knitting thread, or body thread, 40, to the hooks of all the needles, which will thereafter be drawn down by the knitting cams in the usual manner to form a course of plain knit stitches, the loops of the inelastic body thread 40 being drawn on opposite sides of the elastic thread in incorporating it in the fabric, in the manner fully described in my Patent 2,054,217. 'As soon as a complete course of stitches has been formed with the rubber thread incorporated therein, the auxiliary feeding-finger 30 will be drawn into inoperative position, so that part of a course may be knit with the body thread it alone, after which the thread guide 80 can be restored to its operative position to knit the manner disclosed in my Patents 2,230,402,

2,054,217 and co-pending application 201,861, filed April 14, 1938. After making this selvage or non-ravel edge, the knitting of plain knit courses will continue and the elastic thread can be incorporated ineourses at desired intervals by simply moving the feeding-finger 30 into and out of operative position.

It will be understood from the foregoing description that by the construction shown and described, it is practically impossible for the intervening needles 22, in raising, to pass in rear of the elastic thread 20 Or to force it up under the latches of adjacent needles 21 so as to close the latches thereof, and furthermore, when the elastic thread 20 is being fed to the needles 2| below the latches thereof, it will pass in as nearly a straigth line through the delivery eye I of the latch ring as practicable, and the registering delivery 32 of the feeding-finger 30 in a substantially tangential relation to the needle circle, so that all undue friction which might temporarily arrest the forward movement of the elastic thread and cause variations in the tension thereof are positively avoided.

Where I have stated herein that the elastic thread is fed to alternate needles below the latches thereof, it is to be understood that this includes the feeding of the elastic thread upon the latches thereof and then raising these needles to cause the elastic thread to pass below the latches, before the intervening needles are raised in front of the elastic thread.

In my Patent 2,161,250, the auxiliary feeding finger 30 for the elastic thread 20 is thrown in and. out of operation by the pattern drum I20 and in my Patent 2,168,869 the auxiliary feedingfinger Si is thrown in and out of operation by the rod 35, which is also controlled by the pattern drum, which is not shown in this patent.

But in this invention it is impossible to throw the auxiliary feeding-finger in and out of operation by connection to a pattern drum because the movements of the pattern drum are synchronized with the rotation of the knitting cylinder. It is necessary in this invention to operate the auxiliary finger 3| by a cam, the movements of which are nont synchronized with the rotation of the cylinder. To obtain the desired control of the auxiliary feeding-finger in this invention use may be made of a gear wheel 402, whicn is driven by the driving shaft of the machine and which is mounted on the same shaft which operates the eccentric for driving the machine in reciprocating motion.

A gear wheel such as 402 is common to many types of circular machines and generally rotates at a lower speed than the cylinder. Another gear wheel 003 is added and is driven by 802 and contains a cam 40%, which comes in contact with projection 405 connected to rod 35 by lever 407. When cam 400 engages cam 405, the finger 3| is thrown into operative position, and when these two cams do not engage the finger Si is thrown out of action by the spring 400.

This mechanism for controlling the auxiliary finger ll is simple but the theory of its operation is more involved, in order to incorporate the clastic thread in portions of successive courses, and it may be illustrated as follows:

Let R be the ratio between the speed of the gear wheel 402 and the speed of the cylinder. This ratio may be 1 to 4, in which case R would be equal to .25.

A-pitch circumference of 402 B-pitch circumference of 403 E-the angular portion of B, which is covered by the sum of the cam 404 and the projection 405.

Then, to accomplish the purpose of this invention it is necessary that I) R times A=B--E 101; X=portion of each successive course in which the elastic thread is to be incorporated. Then If A is 24 inches and R .25, then R times A=6 inches, and 8-1? is 6 inches. This quantity B-E is fixed for any machine, and substituting its value of 6 in Equation 2 we have:

If X=.30

B=6 plus E, B=7.80

cumference of the pitch of 403 is 7.8 inches.

If X=.20

B=6 plus E, B=7.20

In this case, if the portion of the successive courses containing the elastic thread is .20 of each course, then the angular portion of 403 covered by the sum of cam 404 and projection 405 is 1.2 inches on. the pitch circumference of 403, or approximately 60 degrees, and the pitch circumference of 403 is 7.2 inches.

By changing the diameter of wheel 403 and the angular length of cam 404, the elastic thread may be incorporated into any desired portion of each of the successive courses of the fabric.

In the accompanying drawings, the elastic thread 20 is put in and out of engagement with theneedles 2i by raising the auxiliary finger '3l by the rod 35 and cam 404. But this invention may make use of other mechanisms for putting the elastic thread in and out of engagement with these needles. The finger 3| instead of being raised and lowered may accomplish the same purpose by being mounted above the needle circle, and the eyelet 32 of finger 3i made to operate on a radial line within the needle circle. Or the same result may be accomplished by keeping the auxiliary finger stationary and lowering cam 3B0 so that needles 2| will not engage the elastic thread 20, and raising cam 3" again when it is desired to make the needles 2! engage the elastic thread.

Also thesame thing may be accomplished by leaving the finger 3| and cam 366 stationary and controlling the jacks "I so that they do not engage cam 366 when it is desired to for the needles 2| not to engage the elastic thread.

The cam 404 and the projection 405 may operate any mechanical means which will put the elastic thread in and out of the fabric.

In incorporating elastic thread in plain knit,

fabric, there are two well known methods. In one of these methods, the elastic thread is fed below the latches of selected needles, and is not knitted in the fabric but is caught by the sinker wales on each side of the selected needles as the elastic thread is shed over the hooks of these needles. If these selected needles are alternate needles, and there is sufficient tension in the clastic thread, a smooth fabric is produced, as shown in my Patent 2,230,402. This fabric imitates a 1 and 1 ribbed fabric, as alternate wales form the face of the fabric and the intervening walesform the inner face of the fabric.

In the other method for incorporating elastic thread in plain fabric, the elastic thread is fed above the latches of selected needles and behind intervening needles, and is knitted into the fabric with the body thread in those wales which are knitted by the selected needles. When the elastic thread is knitted into this fabric in this manner, every fourth needle is generally selected for receiving the elastic thread, and the contraction of the elastic thread forms vertical ridges in the finished fabric, in which the wales knitted by the selected needles lie on the inner face of the fabric, and the three intervening wales form the ridges on the face of the fabric.

This invention, which provides a method of incorporating the elastic thread in plain fabrics, is equally applicable to each of the fabrics mentioned above. In this invention, the elastic thread is in only a portion of each course, whether the elastic thread is laid in below the latches of selected needles, or if it is knitted by these needles. Or this invention may be used when both of these methods are combined in the same fabric.

In the fabric as shown in Figure No. 9, the wales IS in heavy lines form the face of the fabric, when the elastic thread is allowed to contract under sufficient tension, as shown in my Patent No. 2,230,402, while the wales. i4 shown in lighter lines form the inner face of the fabric. The wales ii are knitted by the needles 2|, which are raised to a higher level by cam 386, as shown in Figure 1. The elastic thread is fed in front of these needles below the latches, as shown in Figure No. 7. The wales H are knitted by the intervening needles 2!. Between wales Ila and Nb, and betwe wales c and Ild, the elastic thread 20 is withdrawn from the fabric for one revolution of the knitting cylinder and floats around the needle circle as the cylinder revolves. This elastic thread 20 is withdrawn from the fabric by the action of cam 404 in raising the feeding-finger 3|, as shown by the dotted portion in Figure No. 3.

When the elastic thread 20 is laid below the latches of the needles 2l, as shown in Figures 1 and 'l, the plain smooth fabric of my Patent No. 2,230,402 may be produced, but the elastic thread has a tendency to slip between the sinker wales l1 and the loops of the body thread 40. This is especially true after the fabric becomes worn and breaks occur in the elastic thread. This slippage of the elastic thread causes the top to lose its shape and elastic properties. This defect may be reduced by kniting loops of the elastic thread at selected points around the circumference of the knitted fabric.

As shown in Figure No. 9, in the wales I6, loops are drawn of the elastic thread 20 by needle 23, which is raised to a lower level by cam 366, as the jack 380, which is under this needle 23, is shorter than the jacks 38!, which are under needles 2|. This needle 23 receives the elastic thread 20 above the latch, as shown in Figure 7. While only one of these needles 23 is shown, there may be several of them on the circumference of the needle circle,

and by knitting certain wales as wale 16, the slippage of broken elastic threadsmay be reduced.

In Figure No. 8, there is shown in dotted lines the elastic thread 20 as it is incorporated according to this invention in the top of a knitted stocking. The elastic thread 20 is in part of each course, and is knitted into the fabric at wale it. As the elastic thread passes from one course to the next succeeding course without passing across any intervening courses, the fabric is not distorted by the elastic thread as is the case in my Patent I claim:

1. A method of incorporating an elastic thread in circular knit fabric, which comprises feeding said elastic thread to the needles on which said fabric is being knitted for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, rotating said needles for one complete revolution in knitting said fabric, re-engaging said elastic thread with said needles, feeding said elastic thread to said needles for only a portion of a succeeding course of said fabric, and repeating the disengaging of said elastic thread from said needles during a complete revolution of said needles in knitting said fabric, and the engaging of said elastic thread with said needles for only a portion of a succeeding course of said fabric.

2. A method of incorporating an elastic thread in circular knit fabric while said fabric is being knitted on a circular bed of knitting needles,

which comprises, engaging said elastic thread with needles in a portion of the circumference of said circular bed as a portion of a course of said fabric is being knitted, disengaging said elastic thread from said needles, rotating said needles for one revolution in knitting said fabric, engaging said elastic thread with needles in a consecutive portion of said circumference as a consecu- 7 said elastic thread to the needles on which said fabric is being knitted for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, re-engaging said elastic thread with said needles after completion of a revolution of knitting by said needles, feeding said elastic thread to said needles for only a portion of a succeeding course of said fabric, and repeating the alternate disengaging of said elastic thread from the needles for a revolution and feeding said elastic thread to the needles for only a portion of a revolution to incorporate said elastic thread in the fabric in substantially spiral form.

4. A method of incorporating an elastic thread in circular knit fabric, which comprises feeding said elastic thread to the needles on which said fabric is being knitted for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, rotating said needles for one complete revolution in knitting said fabric, re-engaging said elastic thread with said needles, feeding said elastic thread to said needles for only a portion of a succeeding course of said fabric, and repeating the alternate disengaging of said elastic thread from the needles for a revolution and feeding said elastic thread to the needles for only a portion of a revolution to incorporate said elastic thread in the fabric in substantially spiral form with portions of elastic thread in successive portions of successive courses.

5. A method of incorporating an elastic thread in plain knit circular fabric, which comprises feeding said elastic thread to the needles on which said fabric is being knitted, in front of selected needles and behind intervening needles, for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, rotating said needles for one complete revolution in knitting said fabric, re-engaging said elastic thread with said needles, and feeding said elastic thread in front of selected needles and behind intervening needles, for only a portion of a succeeding course of said fabric, and repeating the alternate disengaging of said elastic thread from the needles for a revolution and feeding said elastic thread to the needles for only a portion of a revolution to incorporate said elastic thread in the fabric in substantially spiral form.

6. The method of incorporating an elastic thread in plain knit circular fabric, which comprises feeding said elastic thread to the needles on which said fabric is being knitted, in front of selected needles below the latches thereof and behind intervening needles, for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, rotating said needles for one complete revolution in knitting said fabric, re-engaging said elastic thread with said needles and feeding said elastic in front of selected needles, below the latches thereof and in front of other selected needles above the latches thereof and behind said intervening needles for only a portion of a succeeding course of said fabric, and repeating the alternate disengaging of said elastic thread from the needles for a revolution and feeding said elastic thread to the needles for only a portion of a revolution to incorporate said elastic thread in the fabric in substantially spiral form.

7. A method of incorporating an elastic thread in circular knit fabric, which comprises feedin said elastic thread to the needles on which said fabric is being knitted for only a portion of a circular knit course of said fabric, disengaging said elastic thread from said needles, floating said elastic thread across the circle of said needles, re-engaging said elastic thread with said needles after completing a revolution of knitting by said needles, feeding said elastic thread to said needles for only a portion of a succeeding course of said fabric, and repeating the alternate disengaging of said elastic thread from the needles for a revolution and feeding said elastic thread to the needles for only a portion of a revolution to incorporate said elastic thread in the fabric in substantially spiral form.

8. A method of incorporating an elastic thread in circular knit fabric, while said fabric is being knitted on a circular bed of knitting needles, which comprises engaging said elastic thread with needles in a portion only of the circumference of saidcircular bed as a portion of a course of said fabric is being knitted, disengaging said thread from said needles, rotating said needles for one revolution in knitting said fabric, engaging said elastic thread with needles in an adjacent portion of said circumference and repeating said disengaging of said elastic thread from said needles, rotating said needles for one revolution and engaging said elastic thread with needles in successive portions of said circumference, to incorporate said elastic thread in the fabric in substantially spiral form with elastic thread in successive portions of successive courses.

9. A method of incorporating a continuous elastic thread in circular knit fabric as said fabric is being knitted on a knitting machine having a circular series of needles, which comprises feeding said elastic thread to the needles from a thread feed located at a fixed position relative to feeding means for feeding body thread, operating said elastic thread feed to feed elastic thread to the needles during the knitting of a portion of a course of fabric and thereupon to float the elastic thread across the needle circle of the machine during the knitting of approximately a complete course, and repeating said alternate feeding of said elastic thread for a portion of a course and floating of said elastic thread for approximately a course to incorporate said elastic thread substantially spirally in the fabric.

10. A method of incorporating a continuous elastic thread in a circular knit fabric as said fabric is being knitted on a knitting machine having a circular series of needles, which comprises alternately feeding said elastic thread to the needles on which said fabric is being knitted during the knitting of a portion of a course and floating said elastic thread across the needle circle of said machine during the knitting of approximately a complete course, said elastic thread being fed from a thread feed located at a substantially fixed position relative to feeding means for feeding body thread to the needles.

' JAMES L. GETAZ. 

